It can't be a full body suit I don't think. In the original X-Men movies, Mystique walked around in bare feet (eg the scene where she's on the plane). I think the bodysuit will probably cut off at the ankles. Also, her hands will have to be painted as well as it will just look like a glove (and also socks on her feet). So it still brings up the issue of the blue makeup touching her actual skin on her feet, hands and face. That means there's still the problem of skin irritation for Jennifer.

Yeah thats why they need to find a different ingredient or brand for the body paint that they will be using so JLaw won't have skin irritations again.